• Folding and dimerization kinetics of bone morphogenetic protein-2, a member of the transforming growth factor-β family.

      Vallejo, Luis F; Rinas, Ursula; Helmholtz Centre for Infection Research, Braunschweig, Germany. (2013-01)
      The kinetics of folding and dimerization of bone morphogenetic protein-2 (BMP-2), a disulfide-connected, homodimeric cystine-knot protein and a member of the transforming growth factor-β superfamily, was analyzed under a variety of different conditions. Refolding and dimerization of BMP-2 were extremely slow under all conditions studied, and could be described by consecutive first-order reactions involving at least one long-lived intermediate. The rate constants vary from ~ 0.2 × 10(-5) to ~ 3.5 × 10(-5) s(-1), and were strongly dependent on temperature, redox conditions, and the presence of stabilizing or destabilizing ions. In particular, the combined impact of ionic strength and redox conditions on the rates indicates that electrostatic interactions control thiol-disulfide exchange reactions on the path from the unfolded and reduced monomers to the disulfide-connected growth factor in a rate-determining way.
    • Metabolic peculiarities of Aspergillus niger disclosed by comparative metabolic genomics.

      Sun, Jibin; Lu, Xin; Rinas, Ursula; Zeng, An Ping; Helmholtz Centre for infection research, Inhoffenstr. 7, D-38124 Braunschweig, Germany. (2007)
      Aspergillus niger is an important industrial microorganism for the production of both metabolites, such as citric acid, and proteins, such as fungal enzymes or heterologous proteins. Despite its extensive industrial applications, the genetic inventory of this fungus is only partially understood. The recently released genome sequence opens a new horizon for both scientific studies and biotechnological applications.